Flowable glanulates

ABSTRACT

A process for the manufacture of a flowable granulate by means of spray granulation, which comprises using as starting material a formulation in liquid form comprising 
     (a) a substance or a mixture of substances that is in the form of a waxy or cohesive solid at room temperature, and 
     (b) up to 20% by weight, based on the amount of component (a), of a substance having a specific surface &gt;3 m 2 /g that is insoluble in component (a), yields granulates that have a narrow particle size distribution and a low dust content and that are stable to storage.

The present invention relates to a process for the manufacture of aflowable granulate and to a specific granulate manufactured from epoxyresins and substances having a high specific surface that are insolubletherein.

Polyglycidyl compounds are often used today as a reactive component ofcurable compositions, for example as hardeners or cross-linking agentsin powder coating compositions based on polyesters. Many polyglycidylcompounds are liquid or semi-solid at room temperature or slightlyelevated temperature and therefore have only a limited suitability forpowder coating applications.

U.S. Pat. No. 5,525,685 describes solid compositions consisting ofliquid or semi-solid epoxy resins and solid colloidal condensationpolymers of urea or melamine and formaldehyde, which compositions aresuitable as hardeners for powder coating compositions. Thesolidification of liquid epoxy resins requires, however, relatively highquantities of the inert condensation polymer, which results in arelatively low epoxy content in the powder coating composition hardener.

U.S. Pat. No. 5,294,683 describes the preparation of solid solutions bymelting and subsequently cooling a mixture of at least one polyglycidylcompound that is solid at room temperature and at least 5% by weight ofa polyglycidyl compound that is liquid at room temperature. The solidproducts so obtained are substantially free of inert components and havea high epoxy content. In that process, the solid products are obtainedin the form of flakes that have a tendency to cake when stored forrelatively long periods. Before being processed to form powder coatingcompositions, those flakes are ground to powders by various processes(e.g. by cryo-grinding), there being obtained, however, a materialhaving a high dust content and a broad particle size distribution.

The problem of the present invention was to develop a process for themanufacture of free-flowing granulates of defined particle size andnarrow particle size distribution that are stable to storage and have alow dust content.

Granulates having a narrow particle size distribution can generally bemanufactured from liquid products, such as solutions or melts, by theprocess of continuous spray granulation which is described, for example,in U.S. Pat. No. 3,879,855. That process is problematical, however,where the solidification of epoxy resins is concerned. For example, inthe case of spray granulation of the solid solutions described in U.S.Pat. No. 5,294,683, an agglomerating, poorly flowing, lumpy material isobtained.

It has now been found that waxy, semi-solid or cohesive (sticky)materials can be solidified by means of spray granulation without anyproblems to form free-flowing granulates having a low dust content and anarrow particle size distribution by the addition of a small quantity ofa substance having a large surface area that is insoluble therein.

The problem of solidifying waxy or sticky substances or mixtures ofsubstances arises especially in certain applications of polymeric orpolymerisable substances. Use in powder coating compositions, forexample, requires a high dispersibility; in addition, the substanceshould be in the form of a flowable solid that is stable to storage andhas as low a proportion of fine dust as possible.

The present invention accordingly relates to a process for themanufacture of a flowable granulate by means of spray granulation, whichprocess comprises using as starting material a formulation in liquidform comprising

(a) a substance or a mixture of substances that is in the form of a waxyor cohesive solid at room temperature, and

(b) up to 20% by weight, based on the amount of component (a), of asubstance having a specific surface >3 m²/g that is insoluble incomponent (a).

The process of spray granulation is known to the person skilled in theart from numerous publications, for example from U.S. Pat. No.3,879,855, European Patent Applications EP-A-0 087 039, EP-A-0 163 836,EP-A-0 332 929, EP-A-0 600 211 and EP-A-0 787 682, or GermanOffenlegungsschriften DE-A-29 41 637 and DE-A-43 04 809.

Preferably, the spray granulation is carried out as a fluidised-bedprocess.

In principle, spray granulation for the solidification of liquid orsemi-solid epoxy resins can be carried out also as a batch process.

Preferably, however, the process is carried out continuously since, inthe continuous process, the desired narrow particle size distributioncan be set without any problems. Special preference is given to carryingout the spray granulation as a continuous process with sifting delivery.

By varying the process parameters (residence time, incoming airtemperature, product temperature, spray pressure, spray rate, sifter airquantity) granulates having average particle diameters d₅₀ of from 0.1to 10.0 mm can be produced.

Granulates having average particle diameters d₅₀ of from 0.3 to 5.0 mm,especially from 0.5 to 2.0 mm, are preferred.

The starting materials for the process of the invention are in liquidform, that is to say, they may be solutions, suspensions, emulsions ormelts. The liquid products to be sprayed are produced according tocustomary methods by mixing the constituents and, where applicable, bysubsequently heating the resulting mixtures.

When carrying out the process of the invention, the liquid product to begranulated is introduced into the fluidised bed through suitable spraynozzles. One-component nozzles, two-component nozzles ormultiple-component nozzles can be used. The use of two-componentnozzles, three-component nozzles or higher-multiple-component nozzles isadvantageous. Two-component nozzles are especially preferred.

A preferred embodiment is the process of the invention wherein theliquid formulation is a suspension of component (b) in a melt orsolution of component (a).

The substance (b) that is insoluble in component (a) can be in the formof a solid or in the form of a suspension in a solvent, for example inwater.

When two-component nozzles are used, the liquid formulation to begranulated can be mixed in a pre-mixing zone immediately before beingsprayed in. It is also possible for the melt or solution of component(a) and the suspension of component (b) to be supplied separately to athree-component nozzle. In that case, the two components do not mixuntil sprayed. Another preferred embodiment of the invention, therefore,is a process wherein product introduction is carried out viatwo-component nozzles with a pre-mixing zone or via three-componentnozzles and the liquid formulation is produced immediately before beingsprayed in by mixing a melt of the epoxy resin (a) and a suspension ofcomponent (b) in an inert solvent.

The process of the invention is used especially in the solidification ofsemi-solid and waxy or sticky synthetic polymers or correspondingmonomers or oligomers, especially thermosetting resins, as component(a).

Examples of such thermosetting resins are phenolic resins,polyurethanes, unsaturated polyester resins and epoxy resins.

Preferably, an epoxy resin or a mixture of epoxy resins is used ascomponent (a) in the process of the invention.

The epoxy resins that are customary in epoxy resin technology can beused as component (a). Examples of epoxy resins are:

I) Polyglycidyl and poly-(β-methylglycidyl) esters, obtainable byreacting a compound having at least two carboxyl groups in the moleculeand epichlorohydrin or β-methylepichlorohydrin, respectively. Thereaction is advantageously carried out in the presence of bases.Alternatively, such epoxy compounds can also be prepared byesterification with allyl halides and subsequent oxidation.

Aliphatic polycarboxylic acids can be used as the compound having atleast two carboxyl groups in the molecule. Examples of suchpolycarboxylic acids are oxalic acid, succinic acid, glutaric acid,adipic acid, pimelic acid, suberic acid, azelaic acid and dimerised ortrimerised linoleic acid. It is also possible, however, to usecycloaliphatic polycarboxylic acids, such as, for example,tetrahydrophthalic acid, 4-methyltetrahydrophthalic acid,hexahydrophthalic acid or 4-methylhexahydrophthalic acid. It isfurthermore possible to use aromatic polycarboxylic acids, such as, forexample, phthalic acid, isophthalic acid or terephthalic acid.

II) Polyglycidyl or poly-(β-methylglycidyl) ethers, obtainable byreacting a compound having at least two free alcoholic hydroxy groupsand/or phenolic hydroxy groups with epichlorohydrin orβ-methylepichlorohydrin under alkaline conditions or in the presence ofan acidic catalyst with subsequent alkali treatment.

The glycidyl ethers of that type are derived, for example, from acyclicalcohols, e.g. from ethylene glycol, diethylene glycol or higherpoly-(oxyethylene) glycols, propane-1,2-diol or poly-(oxypropylene)glycols, propane-1,3-diol, butane-1,4-diol, poly-(oxytetramethylene)glycols, pentane-1,5-diol, hexane-1,6-diol, hexane-2,4,6-triol,glycerol, 1,1,1-trimethylolpropane, pentaerythritol, sorbitol, and frompolyepichlorohydrins. Other glycidyl ethers of that type are derivedfrom cycloaliphatic alcohols, such as 1,4-cyclohexanedimethanol,bis(4-hydroxycyclohexyl)methane or 2,2-bis(4-hydroxycyclohexyl)propane,or from alcohols containing aromatic groups and/or further functionalgroups, such as N,N-bis(2-hydroxyethyl)aniline orp,p′-bis(2-hydroxyethylamino)diphenylmethane. The glycidyl ethers canalso be based on mononuclear phenols, such as, for example, resorcinolor hydroquinone, or on polynuclear phenols, such as, for example,bis(4-hydroxyphenyl)methane, 4,4′-dihydroxybiphenyl,bis(4-hydroxyphenyl)sulfone, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane,2,2-bis(4-hydroxyphenyl)propane,2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane or3,3,3′,3′-tetramethyl-5,5′,6,6′-tetrahydroxy-1,1′-spirobisindane. Othersuitable hydroxy compounds for the preparation of glycidyl ethers arenovolaks, obtainable by condensation of aldehydes, such as formaldehyde,acetaldehyde, chloral or furfuraldehyde, with phenols or bisphenols thatare unsubstituted or substituted by chlorine atoms or by C₁-C₉alkylgroups, such as, for example, phenol, 4-chlorophenol, 2-methylphenol or4-tert-butylphenol.

III) Poly-(N-glycidyl) compounds, obtainable by dehydrochlorination ofthe reaction products of epichlorohydrin with amines containing at leasttwo amine hydrogen atoms. Those amines are, for example, aniline,n-butylamine, bis(4-aminophenyl)methane, m-xylylenediamine orbis(4-methylaminophenyl)methane.

The poly-(N-glycidyl) compounds also include, however, triglycidylisocyanurate, N,N′-diglycidyl derivatives of cycloalkylene ureas, suchas ethylene urea or 1,3-propylene urea, and diglycidyl derivatives ofhydantoins, such as of 5,5-dimethylhydantoin.

IV) Poly-(S-glycidyl) compounds, for example di-S-glycidyl derivativesderived from dithiols, such as, for example, ethane-1,2-dithiol orbis(4-mercaptomethylphenyl) ether.

V) Cycloaliphatic epoxy resins, such as, for example,bis(2,3-epoxycyclopentyl) ether, 2,3-epoxycyclopentylglycidyl ether,1,2-bis(2,3-epoxycyclopentyloxy)ethane or3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexane carboxylate.

It is also possible, however, to use epoxy resins in which the 1,2-epoxygroups are bonded to different hetero atoms or functional groups; thosecompounds include, for example, the N,N,O-triglycidyl derivative of4-aminophenols, the glycidyl ether-glycidyl ester of salicylic acid,N-glycidyl-N′-(2-glycidyloxypropyl)-5,5-dimethylhydantoin and2-glycidyloxy-1,3-bis(5,5-dimethyl-1-glycidylhydantoin-3-yl)propane.

As component (b) it is possible to use in the process of the inventionin principle all compounds that are insoluble in epoxy resins and thathave the required high specific surface. Such compounds are known to theperson skilled in the art; it is possible to use, for example,adsorbents, such as zeolites, clays (e.g. bentonite), aerosil, micas, oralso inorganic or organic pigments.

Preferably, component (b) is a urea-formaldehyde ormelamine-formaldehyde condensation polymer.

Urea-formaldehyde condensation polymers are especially preferred.Organic white pigments of that kind are commercially obtainable, forexample, under the name Pergopak®.

Preferably, the specific surface of the substances that can be used ascomponent (b) is >5 m²/g, more preferably >10 m²/g and mostpreferably >15 m²/g.

Methods of determining the specific surface are generally known to theperson skilled in the art. The specific surface can be determined, forexample, by a modified BET adsorption of nitrogen by the method of Hauland Dumbgen (Chem.-Ing.-Techn. 35, 586 (1963)).

The amount of component (b) in the compositions according to theinvention is preferably from 0.1 to 15% by weight, more preferably from1 to 10% by weight and most preferably from 3 to 7% by weight, based onthe amount of component (a).

Preferably, for the process of the invention, the solid solutions knownfrom U.S. Pat. No. 5,294,683 as component (a) are combined withurea-formaldehyde or melamine-formaldehyde condensation polymers ascomponent (b).

The invention further relates, therefore, to a granulate manufacturedfrom a composition comprising

(A) an epoxy resin mixture of at least one polyglycidyl compound that issolid at room temperature and at least 5% by weight, based on the totalamount of all the polyglycidyl compounds, of at least one polyglycidylcompound that is liquid at room temperature, at least a portion of thesolid polyglycidyl compounds being in the form of a solid mixed phaseand the solid mixed phase substantially comprising the total amount ofthe liquid polyglycidyl compounds as additional component;

(B) up to 20% by weight, based on the amount of component A, of a solidcolloidal condensation polymer of urea or melamine and formaldehydehaving a specific surface >3 m²/g.

Its use in the spray granulation process requires the composition of (A)and (B) to be in liquid form. If component (A) is in the form of a solidsolution produced by the process described in U.S. Pat. No. 5,294,683,the substance must be melted or dissolved in a suitable solvent beforebeing sprayed. In that case, it is possible to use both inert solvents,such as, for example, acetone, 2-butanone or ethanol, and reactivesolvents, such as, for example, epichlorohydrin. It is, however, alsopossible to use component (A) in the form of a physical mixture of thetwo polyglycidyl compounds.

As the solid polyglycidyl compound, component (A) preferably comprises adiglycidyl ester or a diglycidyl ether.

Terephthalic acid diglycidyl ester is especially preferred as the solidpolyglycidyl compound in component (A).

As the liquid polyglycidyl compound, component (A) preferably comprisesa polyglycidyl ester or polyglycidyl ether having at least threeglycidyl groups per molecule.

Especially preferred liquid polyglycidyl compounds as constituents ofcomponent (A) are trimellitic acid triglycidyl ester, trimesic acidtriglycidyl ester and pyromellitic acid tetraglycidyl ester.

The solid colloidal condensation polymers of urea or melamine andformaldehyde according to component (B) of the compositions according tothe invention and the preparation thereof are described in Makromol.Chem. 120, 68 (1968) and Makromol. Chem. 149, 1 (1971).

The process of the invention is suitable in general for the manufactureof pulverulent commercial forms, especially for the manufacture of waxyor cohesive substances provided for applications in which the freeflowing characteristic, low dust content or an improved dispersibilityis important. In the scope of this invention, the expression “having alow dust content” characterises substances or mixtures of substances inwhich the proportion of particles having a particle diameter <200 μm isless than 2% by volume.

An important advantage of spray granulation is the optimum heat transferin the fluidised bed, whereby the formation of threads and stickingtogether of the particles is prevented. The product yields are veryhigh, especially in the case of the continuous process.

A further advantage is that any solvents present in the startingmaterials are removed during the spray granulation. Using the process ofthe invention it is possible to manufacture from originally waxy andcohesive material a free-flowing granulate of definable particle sizeand narrow particle size distribution that has a low dust content andthat is distinguished by a high stability to storage and an improveddispersibility in formulations.

The granulates manufactured by the process of the invention are suitableas cross-linking agents for substances having epoxy-reactive functionalgroups, e.g. hydroxyl, thiol, amino, amide and, especially, carboxylgroups. Other examples of suitable functional groups are described inLee/Neville, “Handbook of Epoxy Resins”, MacGraw-Hill, Inc. 1967,Appendix 5-1. For many functional groups the addition of a catalyst canbe advantageous. Mixtures of that kind can generally be fully cured attemperatures of from 100 to 250° C. and have a variety of uses, e.g. assurface-coating compositions, melt adhesives, casting resins or mouldingcompositions. Use as cross-linking agents for those epoxy-reactivesubstances which are solid at room temperature or moderately elevatedtemperature is preferred.

An especially preferred field of use of the granulates according to theinvention is that of powder coating applications.

Those powder coating compositions are preferably based on the polyestershaving terminal carboxyl groups that are customarily used in thattechnology. The polyesters preferably have an acid number of from 10 to100 and an average molecular weight (weight mean) of from 500 to 10 000,especially up to 2000. Such polyesters are advantageously solid at roomtemperature and have a glass transition temperature of from 35 to 120°C., preferably from 40 to 80° C. Suitable polyesters are known, forexample, from U.S. Pat. No. 3,397,254.

The invention further relates, therefore, to a powder coatingcomposition comprising a carboxyl-group-containing polyester and agranulate manufactured by the process of the invention.

EXAMPLES

In the Examples which follow, the following substances are used:

Epoxy resin 1: solid solution of 75% by weight terephthalic aciddiglycidyl ester and 25% by weight trimellitic acid triglycidyl ester,prepared according to U.S. Pat. No. 5,294,683;

Pergopak® M2: urea-formaldehyde condensation product having on average0.6% reactive methylol groups and a specific surface of 20±3 m²/g(determined by the BET method), water content approx. 30% by weight;

Pergopak® HP: urea-formaldehyde condensation product having on average0.6% reactive methylol groups and a specific surface of 20±3 m²/g(determined by the BET method), water content approx. 70% by weight;

Aerosil® 200: highly disperse silicic acid

Alftalate® 9952: carboxyl-terminated polyester (manufactured by Hoechst)

Acrylron®: flow auxiliary based on an acrylated polyacrylate(manufactured by Protex)

Catalyst 1: concentrate of a tetraalkylammonium bromide salt

Example 1

33.3 kg of epoxy resin 1 are dissolved with stirring at 55° C. in 66.7kg of acetone. 3.33 kg of Pergopak® M2 and 0.33 kg of Aerosil® 200 areadded to the clear solution, a finely particulate homogeneous suspensionbeing formed. From the suspension so prepared, a granulate is producedin a GPCG-3 system (Glatt GmbH, Binzen, Germany) by means ofdiscontinuous spray granulation. The process parameters are given inTable 1.

Examples 2 and 3

Analogously to Example 1, various amounts of epoxy resin 1 and Pergopakare suspended in acetone. By means of discontinuous spray granulationthere are produced from those suspensions granulates consisting offree-flowing particles having a low dust content and an average particlediameter d₅₀ of approximately 300 μm. In the case of longer processtimes, shifting of the maximum of the particle size distribution tohigher values is observed. The compositions and the process parametersare given in Table 1.

TABLE 1 T_(air, in) T_(prod) p_(atom) r_(spray) Example composition [°C.] [° C.] [bar] [g/min] 1 66.7 kg acetone 70-55 52-44 2.5 10-17 33.3 kgepoxy resin 1 3.33 kg Pergopak ® M2 0.33 kg Aerosil ® 200 2 60.0 kgacetone 65-75 57-45 2.5 18-28 40.0 kg epoxy resin 1 4.0 kg Pergopak ® M23 60.0 kg acetone 65-80 48-38 2.5 14 40.0 kg epoxy resin 1 2.0 kgPergopak ® M2 T_(air, in): temperature of incoming air T_(prod): producttemperature p_(atom): spray pressure r_(spray): spray rate

Examples 4 and 5

33 g of epoxy resin 1 are dissolved with stirring at 75° C. in 67 g ofepichlorohydrin. 1.65 g of Pergopak® M2 (Example 4) or Pergopak® HP(Example 5) are added to the clear solution, a finely particulatehomogeneous suspension being formed. From the suspension so prepared, agranulate is produced in a GPCG-3 system (Glatt GmbH, Binzen) by meansof discontinuous spray granulation. The process parameters are given inTable 2.

TABLE 2 T_(air, in) T_(prod) p_(atom) r_(spray) Example composition [°C.] [° C.] [bar] [g/min] 4 66 g epichlorohydrin 86-74 73-44 2.5 5-17 33g epoxy resin 1 1.65 g Pergopak ® M2 5 66 g epichlorohydrin 92-65 71-442.5 6-10 33 g epoxy resin 1 1.65 g Pergopak ® HP T_(air, in):temperature of incoming air T_(prod): product temperature p_(atom):spray pressure r_(spray): spray rate

Example 6

15 kg of epoxy resin 1 are melted at 140° C. With stirring (propellerstirrer), 0.75 kg of Pergopak® HP is added; the resulting meltsuspension is subsequently homogenised with a high-speed stirrer(Ultra-Turrax). That preparation step is necessary to prevent cloggingof the nozzle by relatively large Pergopak agglomerates. Thelow-viscosity melt suspension so obtained (viscosity: approx. 100-200mPa.s) is fed to the spray nozzle by means of a peristaltic pump, thehose lines being heated electrically. In a GPCG 15 fluidised-bed system(Glatt GmbH, Binzen), a granulate is produced from the melt by means ofdiscontinuous spray granulation. The spray arrangement is a so-called“top spray” design, that is to say, with the spray direction from top tobottom counter to the incoming air stream using a two-component nozzlemanufactured by Schlick having a hole diameter of 2.2 mm. The relevantprocess parameters are given in Table 3. The granulates produced have alow dust content, are free-flowing and are distinguished by a looseparticle structure which facilitates dispersibility in the preparationof powder coating compositions.

Examples 7-11

30 kg of epoxy resin 1 are melted in a liquid-temperature-controlledheating tank (temperature of the heating medium approx. 150° C.). Afterthe melt has cooled to 100° C., 1.5 kg of Pergopak® HP (Example 7) orPergopak® M2 (Examples 8-11) are added and suspended with stirring(turbo stirrer). To deliver the melt suspension at high spray rates(10-49 kg/h) a gear pump (Netsch Mono Pump) is used. In an AGT 400fluidised-bed system (Glatt Ingenieurtechnik GmbH, Weimar, Germany) agranulate is produced from the melt by means of continuous spraygranulation. The spray direction is from bottom to top (in the directionof the incoming air) using a two-component nozzle manufactured by Glatthaving a hole diameter of 5 mm. All the components of the melt feed lineare heated electrically. The granulated product is removed from theproduct vessel continuously through a centrally arranged, singlecounterflow sifter. The quantity of classifying air is 90-140 m³/h. Therelevant process parameters are given in Table 3.

Example 12

A melt of epoxy resin 1 and an aqueous suspension of Pergopak® M2 (15%by weight solid) are fed separately to a two-component nozzle having ashort mixing section. After a relatively short mixing time (approx. 10seconds residence time), the mixture is sprayed in the form of amulti-phase system.

TABLE 3 Exam- process T_(air, in) T_(prod) F_(air) p_(atom) r_(spray) yple type [° C.] [° C.] [m³/h] [bar] [g/min] [%] 6 batch 40 40 400 4.0  6.4 98   40 40 7 continuous 42 38 1051 2.0 25-49 98.6 33 44 1208 8continuous 38 32 958 2.0 10-42 96.0 43 44 1204 9 continuous 43 40 10942.0 21-26 95   40 45 1251 10 continuous 30 36 1000 3.0 25 97.0 30 371010 11 continuous 29 37 1139 3.0 34 97.0 29 37 1137 12 continuous 46 241063 3.0 23 (melt) 52 36 1184 13 (slurry) T_(air, in): temperature ofincoming air T_(prod): product temperature F_(air): quantity of incomingair p_(atom): spray pressure r_(spray): spray rate y: yield

Examples of Applications

The granulates produced in Example 9 (granulate 1, average particle size2 mm) and 10 (granulate 2, average particle size 1 mm) are mixed withthe substances indicated in Table 4 and homogenised at 90° C. in atwin-screw extruder (Prism TSE 16 PC). When cool, the extrudate isground to an average particle size of 40 μm (Retsch ZSM 1000ultracentrifugal mill). Particles having sizes >100 μm are removed bysieving. The gelling times of the powder coating compositions measuredin accordance with ISO 8130 are given in Table 4. The powder coatingcomposition is electrostatically sprayed onto test plates (chromatizedaluminium) and stoved at 200° C. for 15 minutes. The properties of thecoatings so produced are listed in Table 4 (Examples I and II).

In the Comparison Examples III and IV, flakes of pure epoxy resin 1(hardener 3, average particle size 8 mm) and a powder produced fromthose flakes by cryo-grinding (hardener 4, average particle size 3 mm)are respectively used as powder coating composition hardeners. Theresults show that the powder coating compositions with the granulatesaccording to the invention provide comparable properties, but have aconsiderably higher stability to storage.

TABLE 4 Example I II III IV granulate 1 [g] 4.55 granulate 2 [g] 4.53hardener 3 [g] 4.21 hardener 4 [g] 4.21 Alftalat ® 9952 [g] 59.41 59.4359.76 59.76 benzoin [g] 0.20 0.20 0.20 0.20 Acrylron ® [g] 1.50 1.501.50 1.50 catalyst 1 [g] 1.0 1.0 1.0 1.0 TiO₂ (Cronos 2160) [g] 33.3333.33 33.33 33.33 properties of the unhardened powder coatingcomposition: gelling time at 180° C. [s] 200 185 180 205 powderquality¹⁾ after 3 days' storage 8 8 8 6 after 7 days' storage 8 8 7 5after 14 days' storage 8 8 7 7 after 21 days' storage 8 7 6 5 after 28days' storage 8 7 5 properties of the hardened powder coatingcomposition: layer thickness [μm] 67 65 56 60 impact deformation, rearside 160 160 160 160 [kg · cm] gloss at an angle of 20° [%] 86 85 88 89gloss at an angle of 60° [%] 94 94 95 95 ¹⁾powder quality: measure ofthe resistance of the powder to caking (“caking resistance”); isdetermined after storage at 40° C. and evaluated visually with ratingsfrom 1 to 10, wherein 10 = unchanged, 0 = agglomerated; formulationswith ratings >5 can be applied

What is claimed is:
 1. A process for the manufacture of a flowablegranulate by means of spray granulation, which comprises using asstarting material a formulation in liquid form comprising (a) asubstance or a mixture of substances that is in the form of a waxy orcohesive solid at room temperature, and (b) up to 20% by weight, basedon the amount of component (a), of a substance having a specificsurface >3 m²/g that is insoluble in component (a).
 2. A processaccording to claim 1, wherein the spray granulation is carried out as afluidised-bed process.
 3. A process according to claim 1, wherein thespray granulation is carried out as a continuous process.
 4. A processaccording to claim 1, wherein the spray granulation is carried out as acontinuous process with sifting delivery.
 5. A process according toclaim 1, wherein the liquid formulation is a suspension of component (b)in a melt or a solution of component (a).
 6. A process according toclaim 1, wherein product introduction is carried out via two-componentnozzles, three-component nozzles or higher-multiple-component nozzles.7. A process according to claim 1, wherein component (a) is an epoxyresin or a mixture of epoxy resins.
 8. A granulate manufactured by theprocess according to claim
 1. 9. A granulate according to claim 8,manufactured from a composition comprising (A) an epoxy resin mixture ofat least one polyglycidyl compound that is solid at room temperature andat least 5% by weight, based on the total amount of all the polyglycidylcompounds, of at least one polyglycidyl compound that is liquid at roomtemperature, at least a portion of the solid polyglycidyl compoundsbeing in the form of a solid mixed phase and the solid mixed phasesubstantially comprising the total amount of the liquid polyglycidylcompounds as additional component; (B) up to 20% by weight, based on theamount of component A, of a solid colloidal condensation polymer of ureaor melamine and formaldehyde having a specific surface >3 m²/g.
 10. Agranulate according to claim 9, wherein component (A) comprises adiglycidyl ester or a diglycidyl ether as the solid polyglycidylcompound.
 11. A granulate according to claim 9, wherein component (A)comprises terephthalic acid diglycidyl ester as the solid polyglycidylcompound.
 12. A granulate according to claim 9, wherein component (A)comprises a polyglycidyl ester or polyglycidyl ether having at leastthree glycidyl groups per molecule as the liquid polyglycidyl compound.13. A granulate according to claim 9, wherein component (A) comprisestrimellitic acid triglycidyl ester, trimesic acid triglycidyl ester orpyromellitic acid tetraglycidyl ester as the liquid polyglycidylcompound.
 14. A granulate according to claim 9, wherein component (B) isa urea-formaldehyde condensation polymer.
 15. A granulate according toclaim 9, wherein component (B) has a specific surface of >5 m²/g.
 16. Agranulate according to claim 9, comprising from 1 to 10% by weight ofcomponent B, based on the amount of component A.
 17. A powder coatingcomposition comprising a carboxyl-group-containing polyester and agranulate manufactured by the process according to claim 7.